Method of making cartridge cases



lvg 26, 1947. R. H. WALLACE ETAL A 2,426,289

-METHOD OF MAKING CARTRIDGE CASES ALEX W- KNUDS'EIN:

ROBERT H. WLLAC Aug. 26, 1.947. R. WALLACE ErAL 2,426,239

METHOD OF MAKING CARTRIDGE CASESl Filed June 14, 1941V 2 sheets-sheet 2F|G.2 2o .5 I4 756 4 :alp s 3 "":l' l: I

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,A l l ls l l mvENToRS ALEX W. KNUDSEN "Y` RoERTwwALLAcEJ Patented Aug.26, 1947 A.

'NED STAT-ES METHOD F MAKING CARTRIDGE 'CASES Application June 14,1941', Serial No. 398,174

.3 Claims.

This invention relates to new and useful improvements in the vmethod ofVmaking two piece cartridge cases.

An important object vof the invention is to :provide vmethod and meansfor press fitting, squeezing and upsetting theparts of 'the casetogether to form a double seal to effectively withstand high gas andhydrostatic pressures.

Another important object of the invention is to provide a cartridge casemade of two simple parts to replace the more 'expensive `one-piece drawncases, which two `parts lare most effectively locked together with a newmethod of manufacture.

Other objects and advantages will become apparent during the course of'the following description.

In the accompanying drawings forming a part of the description andwherein like parts 'are designated with like numerals throughout `theseveral views,

Fig. 1 is a longitudinal section through the improved cartridge caseshowing the same 'as it takes its assembling position between dies,

Fig. 2 is a similar View showing an intermediate step in the method ofconnecting the `case with the base,

Fig. 3 is another similar view showing the i-nal step in the method,illustrating'the nalassembled condition of the parts,

Fig. 4 is an enlarged fragmentary section of the case and dies of Fig.1.

Fig. 5 is an enlarged and magnified section of the case and dies asshown in Fig. 3, illustrating the final form of the joint between thecase and the base.

Referring now more in detail to the accompanying drawings and to Figs. 1and 4, wherein for the purpose of illustration is shown a 105 millimetercartridge case, the numeral I designates an elongated cylindrical bodyor .metal cartridge case about fourteen inches in length, preferablymade of seamless or welded tubing Vhaving an O. D. of approximately 4%inches, and of uniform wall thickness of approximately le of an inch.Tubing having a longitudinally welded seam has been found to giveexcellent results and as not being impaired at the seam in the yflangingand `processing steps.

The cap or base end of the Ycartridge case or annulus I is formed in anysuitable way, but preferably by spinning, with an inwardly taperedportion 2 bent on a ,1 5 inch radius at vapproximately an angle of 45degrees, the end `'of which .portion is bent again on a ,-16 inch radiusinto an axially 'extending portion having the same wall thickness as the-body of the case and an I. D. of 13% inches anda length of 1/8 inchconcentric with the main body -of the case. This bending of Ithe Iend'of the lcase forms it with the integral compound curved -ange 2 and 3as illustrated.

vThe -b'ase 'of the cartridge case is made of a disc cut from round barstock, or it may be a stamping, forging, casting or the like. In any`event it is formed on its inner face with an axially extending 764 inchwide groove 5 formed with concentric axial iianges 6 and l. The innerflange 5 has an O. D. of 32%2 inches and is much longer than the outerflange l which stands Tse of an inch 'from the outer face of the base tothe tip of the ange, while the inner ange stands l inches .from the sameface of the base to its tip. The base also has an annular collar orflange 8 and a central inwardly extending boss 9 which is bored ortapped for the fuse capy of the primer charge. The outer face of theouter flange 'l is tapered at 4an angle of 7 degrees while its innerface has a '45 degree angle. The outer face of @ange t is .perfectlycylindrical and normal to the base, while its inner face at its tip isinclined at 'an angle of 15 degrees to merge into its transverse endwith a Tg inch radius and into base 'd 1on a -g inch radius. Thus thebase is provided with a groove 5 which is 1/54 of an inch wider than thewall thickness of the flange end -3 of the 'case to freely receive suchend and to provide for rapid centering and alignment thereof 'as welllas to provide for the subsequent thickv4ching or upsetting of the endwithin such groove. The method of assembling the base t on the case I,is to insert the latter in a slide t ring die Il) which in thisillustration, has a die cavity terminating in a 20 degree angle bottomI2 to bac-k up the outer iiange 1. This ring die is seated in a ca vityin the upper end of a hollow stand I3 and is held by a ring retainerplate secured tc the stand by screws It as shown. When the case :I isinserted through the ring die Il) and down into the hollow stand, it hasa clearance with the .bore through the stand as illustrated, and the proi'ectile end of the case is supported upon a spring pad, not shown,inthe base of the stand to permit .axial .movement of the case duringassembling :and may Iserve to eject the case later in the usual manner.A 4male die .post I5 is disposed concentric and longitudinally in thehollow stand to removably support the male die Il on top of the post bymeans of a screw I8 and within the female die with clearancetherebetween for insertion ofthe case. The upper portion of the male dieIl is formed with a convex nose swung on a 1/2 inch radius merging intoan annular shoulder l 9 arranged a distance below the cavity I2 of thefemale die so that the cylindrical wall of the female die rmly backs upthe cylindrical case during the processing.

The base il is then placed upon the case with the flange 3 entered inthe groove 5 as shown in Figs. 1 and 4, and with the tip of the innerbase flange engaging the convex surface of the male die Il and the endof flange 3 bottomed in the groove 5. The punch or ram 2!) of the pressis then lowered to engage the base to move the case down through thering die Iii and into the stand i3. As the base and case are beingforced downwardly by the ram, the tip of the inner flange S of the baseis first ilared outwardly by the male die I?, into engagement with thecase I below the cavity I2 in the female die IQ, as shown to advantagein Fig. 2. As the case is forced farther downwardly into the female dieI0, the nose of the male die il causes the inner ilange to progressivelypinch or squeeze more and more of the case against the female die withlongitudinal and radial outward pressure. This causes the metal of thecase in the area between the inner flange ii and female die to crowd orflow longitudinally into the flanged portions 2 and 3. This longitudinaldisplacement of metal causes the flange 3 to upset and increase in wallthickness above that of the original case I to pack and completely llthe wider groove 5 in the base.

It will be appreciated that the inner flange 5 of the base has its innertip surface beveled for coordination with the curvature of the male dieso that the. flange will be progressively moved with progressivelyincreasing pressure into engagement with the case, to iron this portionof the case longitudinally and against the wall of the female die andagainst the outer flange 'l which backs up the flanged portion 2 of thecase, whereby the displaced metal will be squeezed into and thicken theextremity 3 while portions of the two ilanges are being simultaneouslypressed toward one another to firmly lock this thickened iiange into thebase. When the outer flange I moves down into the female die cavity I2,it is pressed inwardly to closely engage the flange 2 and densifymolecular structure of the flange 1. As the 1/2 inch radius of the maleydie I'I bottoms against the 1%@ radius of the base 4 it will be seenthat the base portions of flange 6 engaging the flange portions 2 and 3will be thinned and compacted firmly against and lock the thickened caseflange in its space between the nanges 6 and l. In the final pressurestage of the press, the shoulder I9 of the male die engages the extremeend of the ilange 6 to deform it into a thin annular fin or flange 22which seals against the shoulder formed in the case and serves as a illlor reinforcement for the end of the thinned portion of the case.

After the dies have bottomed and have formed the joint as shown in Fig.5, the ram is elevated, and either the spring pressure pad or the maledie can be automatically moved upwardly to assist in ejecting the shell.Thereafter, the base 4 is machined down to the dash line 25 shown inFig. 5 to ilnish its exterior, or the base may be pre-shaped to nal formbefore being attached to the case.

The grain or fiber of the metal base 4 extends lengthwise of the flangesand is compacted in the outer flange adjacent the flange 2 while thegrain of the inner flange 6 is compacted and follows the contour of thecompound bend of the anges 2 and 3 as best shown by the dot and dashlines in Fig. 5. Any stress imposed upon the joint formed, createsleverage inthe vicinity of the two points E3 and 2@ at opposite surfacesof the ange to create a compound compression seal. Hydrostatic pressuretests prove the joint invulnerable and show that the cylindrical contourof the case is maintained about 1A; of an inch beyond the iin 2 andtoward the projectile end of the shell indicating the supreme strengthof the joint under tests which are so severe as to actually bow the caseoutwardly.

While the parts of the cartridge case may be made from any kind ofmetal, the present invention was devised in order that it could beefcaciously made of steel to replace the more expensive one piece drawnbrass cases. In this connection, the cylindrical body I of the case ispreferably made of steel tubing possessing a single longitudinallyextending welded seam for effecting economy of materials in theconstruction of the case. The method of processing the device, and itsconstruction were conformed, to compensate for working of the metal toobviate any danger of impairing or opening the welded stock, so thatthis less expensive material could be utilized to economize in themanufacture of this essential defense material. The case is made simplyin two pieces which are united very rapidly in a manner to provide acase which is more resistant to impact than the former brass cases, andis stronger at the joint than former multiple piece cases. The cases canbe rendered rust-proof in various ways, so that they can be stored forindefinite periods or reused, and one eillcacious method is toelectro-plate the cases with a thin coat of copper when completed.

It Iwill of course be appreciated that the invention is not limited tothe production of cartridge cases, but may be employed as a joint ofgeneral application between any form of annulus and end closure. It willalso be understood that various changes in the size, shape and relationof parts may be resorted to without departing from the spirit of theinvention or the scope of the appended claims.

We claim:

l. The method of uniting a metallic annulus with a groove in a metallicbase dened between a pair of spaced inner and outer annular flanges,said groove bein-g slightly wider than the wall thickness of saidannulus, inserting the annulus into a conning die with its end insertedinto said groove, moving said base and annulus axially relative to saiddie to restrict radial movement of said annulus, moving a male dieagainst said inner flange to force the same radially outward to pinchthe annulus against said confining die, and as the base and annulus aremoved further to cause the inner ilange to progressively iron the metalof said annulus out against said conning die to flow the metal of saidannulus axially thereof as the outer flange is moved to engage theconfining die to thereby form a continuation of said confining die walland thereafter exerting radially outward and axial pressure upon saidinner flange causing metal of the annulus to flow toward the end thereofto thicken the same in said groove while continuing radial inward andoutward pressures upon the outer and inner flanges respectively to locksaid thickened portions of said annulus within said groove.

2. The method of uniting a metallic annulus with a groove in a metallicbase defined between the high inner base flange having a straightouterwall and a low outer base flange having an inner Wall inclinedoutwardly away from the inner flange, bending the end of said annulusinwardly into a compound Ibend with a reduced inclined portionapproximating the length of said inclined wall of said outer ange andterminating in an axially extending end, inserting said annulus forlimited axial movement in a radial conning die with said reduced axiallyextending terminal of said annulus positioned in said groove betweensaid inner and outer iianges, moving said base and annulus axially ofsaid die while forming the end of said inner ange outwardly whereby itsfree edge pinches the annulus below said compound bend against saidconfining die, continuing the movement of said annulus axially of saiddie and exerting radial outward pressure on said inner flange to causethe same to be ironed out against the annulus backed up by saidconfining die, said outer flange being moved axially against saidconfining die to back up said annulus as said inner iiange isprogressively squeezed inwardly and axially from its free edge therebycausing the metal of said annulus to progressively iiow into the reducedend thereof and to crowd its metal into said groove to increase its wallthickness while said two flanges are forced toward each other againstopposite sides of the thickened reduced end of the annulus.

3. The method of mounting a steel annulus with a base consisting ofproviding a base having a groove wider than the wall thickness of saidannulus, inserting the end of said annulus in said groove, exertingradially outward pressure upon that portion of the annulus immediatelyadjacent the inserted end of the annulus while confining the exterior ofsaid portion of the annulus, and exerting axial pressure on saidannulus, said axial and radial pressure serving to thicken said end insaid groove above the original wall thickness of the annulus, andconcurrently with the exertion of said axial and radial pressure,compressing the walls dening said groove upon the thickened end in thedirection of said thickening.

ALEX W. KNUDSEN. ROBERT I-I. WALLACE'.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 192,676 Bullard July 3, 18771,826,544 Herbig Oct. 6, 1931 1,649,409 Jardine Nov. 15, 1927 1,805,255Osterholm May 12, 1931 1,691,778 McDonald Nov. 13, 1928 2,018,683 MeyerOct. 29, 1935 2,245,298 Proctor June 10, 1941 339,812 Ritchie Apr. 13,1886 1,527,471 Clinchy et al Feb. 24, 1925 1,686,562 Jackson Oc'. 9,1928 1,923,546 Lindemann et al. Aug. 22, 1933 1,292,359 Nelson Jan. 21,1919 498,856 Overbaugh June 6, 1893 387,651 Maxim Aug. 14, 18881,157,269 Wall Oct. 19, 1915 1,482,932 Keiner Feb'. 5, 1924 546,936Pinfold Sept. 24, 1895 750,394 Reynolds Jan. 26, 1904 1,620,728 JacksonMar. 15, 1927 Re. 7,647 Allen May 1, 1877 298,696 Kynoch May 13, 18841,921,021 Bungay Aug. 8, 1933 2,112,673 Lewis Mar. 29, 1938 2,130,699Reinartz Sept. 20, 1938 FOREIGN PATENTS Number Country Date SwitzerlandApr. 24, 1912

